Funding is requested to continue support of an interdisciplinary training program in molecular biophysics at UT Southwestern. This program was initiated in 1988 as an informal training program with faculty drawn from several different graduate programs. The reorganization of the graduate school at UT Southwestern in 1990 gave us the opportunity to establish a formal Graduate Program in Molecular Biophysics within the Division of Cell and Molecular Biology. Graduate students are admitted first to the Division, then choose to enter the Molecular Biophysics program following their first year. Training funds are used to support qualified students once they have selected the Molecular Biophysics program. Our program is directed towards a population of students with strong backgrounds in the physical sciences (math, chemistry, and physics). Recruitment efforts are aggressive and include special efforts targeted to chemistry, physics, and engineering undergraduate programs. All students in the Division take the same first year course, which provides background in biochemistry, biophysics, genetics, immunology, and cell biology. First year students also do three to four lab rotations. Upon entering the Molecular Biophysics Graduate Program, students make take advanced courses including a required one-semester course in biophysical methods and physical chemical descriptions of macromolecular properties. Other courses are a half-semester in length. Four of these additional advanced courses must be completed, two from the group of courses that emphasize methods (X- ray diffraction, optical spectroscopy, magnetic resonance spectroscopy,...) and two from the group of courses that emphasize applications (protein structure and folding, biological membranes,...). Students must pass a qualifying examination at the end of the second year. The exam is an oral defense of a research proposal in molecular biophysics on a topic not directly related to the student's own research project. Students select a mentor for their dissertation research upon completion of their lab rotations. Their dissertation committee is convened after they have completed the qualifying exam. Principal research areas represented by the twenty-four Molecular Biophysics graduate faculty are X-ray crystallography, nuclear magnetic resonance spectroscopy including both in vivo and high resolution, optical spectroscopy, video-enhanced light microscopy, fluorescence recovery after photobleaching, and electron microscopy. Research problems actively under investigation include the regulation of G-protein coupled receptor system, the intracellular movement of vesicles, the structure/function relationship of intracellular proteinases, and fundamental studies of protein folding and protein sequence/conformation/functional relationships. Facilities for trainees to carry out their research projects are excellent with superb instrumentation. The research laboratories are housed in the basic sciences buildings of UT Southwestern including the Howard Hughes Medical Institute and our recently constructed North Campus facility.